Vacuum cleaner brush drive



y 1950 D. H. REEVES 2,513,587

VACUUM CLEANER BRUSH DRIVE Filed Nov. 20, 1944 Fig.1

Fig. 2

. I6 58 5'6 64 54 4 II [I l I I l I .f Ell x /4 5.2 18 1o INVENTOR.

MWKM 8W Mm! Patented July 4, 1950 Donald H. Reeves,,Dayton, ilhio,assignor to Genoral Motors Corporation, Dayton, Ohio, a corporation ofDelaware Application November 20, 1944, Serial No. 564,306

7 Claims.

This invention relates to a domestic appliance and more particularlytoan improved iorm oi vacuum cleaner.

One object of this invention is to provide an automatic means foradjusting the height of the agitator.

Another object oi this invention is to provide a height adjustingmechanism which will automatically compensate for brush wear.

Another object of this invention is to provide an improved agitatordrive mechanism which eliminates the need for a belt.

Still another object of this invention is to provide an improvedoverload release between the agitator and the driving motor.

It is another object of this invention to provide a hydraulic fluiddrive between the vacuum cleaner motor and the brush which makes itpossible to operate the agitator at the most desirable speed forconserving the brushes and at the same time efilciently cleaning the rugsurface.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings, wherein a preferred form of element It. The elements it arepivoted to the casing In by suitable pivots such as the pivot it so thatmovement'oi each element It about its pivot it will cause an adjustmentin the height of the agitator it relative to the nozzle opening it.

Referring now to Fig. i. of the drawings, reference numeral 2%designates an electric motor which is used for supplying power foroperating the main vacuum cleaner fan as through any suitable drivemeans (not shown). The motor operates a fluid pump as which forms a partof a hydraulic system for driving the agitator it and for adjusting theheight or the agitator it relative to the surface to be cleaned. Fluidunder pressure is discharged from the pump through the line 26 havingone branch 28 leading to the pressure relief valve 39, another branch 32leading to a height adjusting mechanism generally designated by thereference numeral 34,

. 2 and a third branch 36 leading to a fluid motor 38 located at one endof the agitator l4 and directly connected to the agitator shaft 40 so asto operate the agitator. Reference numeral 42 designates a fluidreservoir oi the type commonly used in hydraulic power systems, andreference numeral 44 designates the fluid return line leading to theinlet of the pump 28.

If for any reason the agitator becomes jammed so as not to allow themotor 38 to operate, an excessive pressure will be built-up at theoutlet of the pump 24 with the result that the relief valve 30 will openand allow the fluid to return to the inlet of the pump 24. A spring 50normally holds the relief valve 30 in its closed position and is ofsufficient strength to hold the valve 30 closed at all times except whenthe agitator becomes jammed.

During normal operation of the motor 20, fluid will be supplied by thepump 28 for operating the agitator H at the desired speed. By virtue ofthe use of a hydraulic drive from the main motor 20 to the brush l4 itis possible to design the system so as to operate'the brush it at anydesired speed. In order to simplify this disclosure, the internalmechanisms .of the pump 26 and the motor 38 have not been shown ashydraulic motors and pumps of this type are now well-known and commonlyused in a large number of applications.

The fluid leaving the pump 24 is supplied under pressure to the motor 38and the pressure within the lines 28, 32, and 36 will be determinedlargely by the amount or power required to operate the agitator it.Thus, whenever the agitator it is too low so that it brushes the carpetor other surface to be cleaned too vigorously, an excessive amount ofpower will be required with the result that an excessive amount 01'pressure will build up within the height adjusting mechanism 3 2.

The height adjusting mechanism comprises an outer casing 52 within whichthere is provided a pressure responsive bellows 5t for operating theplunger 56 which has its inner end secured to the end wall 58 oi thebellows 54 and has its outer end pushing against the projection-6dprovided on the arm 62 of the bracket it. A suitable spring 6%, arrangedas shown, tends to bias the pin 56. and the agitator bracket it into aposition in which the agitator contacts the surface to be cleaned withthe maximum desired pressure. The force of the spring Ed is partiallyovercome by the fluid pressure built-41p within the casing 52 duringoperation of the pump 26.

The spring Ed is designed to exert just enough force to maintain theagitator Hi at the most eflicient height for proper cleaning.

The agitator M is preferably of the type employing tour spirallyarranged brush segments amass? which extend the full length of theagitator. Inasmuch as the construction of the agitator is broadlyimmaterial, the agitator has been shown somewhat diagrammatically inorder to eliminate needless details.

For purposes of illustration, I have shown an arrangement in which theheight adjusting means adjusts the height of the agitator without in anyway adjusting the height of the nozzle,

whereas, it is within the purview of this invention to utilize a heightadjusting means of this type for elevating both the agitator and thefloor nozzle within which the agitator is disposed.

The agitator supporting brackets l6 are preferably mounted to move inunison and to be actuated by a single height adjusting mechanism.However, each bracket 16 could be individually operated by a separateheight adjusting means both of which would be connected into thehydraulic system in the manner shown.

While the form of embodiment of the invention as herein disclosedconstitutes a preferred form,

it is to be understood that other forms might be 1 adopted, as may comewithin the scope of the claims which follow.

What is claimed is as follows:

1. In a vacuum cleaner, 9. housing having a ing a member movable inresponse to changes in the pressure in said lines, and means wherebymovement of said member causes movement of the means for adjustablysupporting the agitator in a direction away from said nozzle opening.

2. In combination with a rotary surface treating element, a biasingarrangement for biasing the surfacing treating element toward thesurface to be treated, a hydraulic system including a pump and ahydraulic motor drivingly connected to said rotary element, and meansresponsive to the pressure in the hydraulic system at the inlet of saidhydraulic motor for reducing the pressure between the rotary element andthe surface being treated.

3. In a. vacuum cleaner, a housing having a floor nozzle opening, arotatable agitator member disposed within said/nozzle, a biasingarrangement for biasing the agitator toward the nozzle opening, a motor,a hydraulic system for transmitting power from said motor to saidagitator, said system including a pump operated by said motor and ahydraulic motor for rotating said agitator, and means responsive tochanges in the pressure at. the inlet of said hydraulic motor forcontrolling the height of said agitator relative to said nozzle opening.

4. In a vacuum cleaner, a nozzle member having an air inlet opening, anagitator member adjacent said opening, means for adjustably supportingsaid agitator member relative to the surface to be cleaned, said meansincluding a biasling arrangement for biasing the agitator member towardthe surface to be cleaned, fan means for creating a suction at saidnozzle opening, a. motor, a hydraulic system for transmitting power fromsaid motor to said agitator member, and

means opposing said biasing arrangement and responsive to an increase inpressure in said system between the motor and the agitator for adjustingsaid agitator member in a direction away from the surface to be cleaned.

5. In a vacuum cleaner, a nozzle member, a rotatable agitator memberadapted to agitate the surface of the material to be cleaned, afan forcreating a suction at the nozzle of said nozzle member, an electricmotor for operating said fan, power transmitting means whereby saidmotor imparts rotation to said agitator member, said power transmittingmeans comprising a hydraulic system including hydraulic pump means and ahydraulic motor, a biasing arrangement for biasing the agitator memberout through the nomle of the nozzle member and means responsive to anincrease in the pressure in said system for I retracting the agitatormember relative to the nozzle of the nozzle member.

6. In a vacuum cleaner, a nozzle member, an electric motor, a fluid pumpoperated by said motor, an agitator disposed within said nozzle member,means for biasing said agitator toward the surface to be cleaned, ahydraulic motor drivingly connected to said agitator, fluid flowconnections between said pump and said hydraulic motor, said pump havingan inlet and an outlet, means for by-passing fluid from the outlet ofsaid pump to the inlet of said pump in response to a predeterminedpressure at the outlet of said pump, and means responsive to increase inpressure in said connections for opposing the action of said biasingmeans.

7. In a vacuum cleaner, a housing having a floor nozzle opening, anagitator disposed within said nozzle opening for frictionally engagingthe material to be cleaned, adjustable means for'adjusting the locationof the agitator within the.

nozzle opening for varying the degree of frictional engagement so as tovary the amount of agitation, said adjustable means including a biasingarrangement for biasing the agitator out of the nozzle opening, ahydraulic pump, a hydraulic motor drivingly connected to said agitator,fluid flow lines between said pump and said motor,

and means responsive to an increase in the pressure within a portion ofsaid lines for retracting said adjustable means to draw the agitatorfurther into the nozzle opening so as to limit the degree of frictionalengagement between said agitator and the surface to be cleaned.

DONALD H. REEVES.

REFERENCES CITED The following references are of record in'the file ofthis patent:

UNITED STATES PA-TENI'S 564,459 Great Britain Sept. 2a, 1944

